Critical Thinking

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Critical Thinking
Answer each of these questions. Be sure to refer to any outside links given.

This activity contains 3 questions.

What is the current date? Based on your personal observations and/or knowledge of seasonal change, has day length and altitude of the Sun been increasing or decreasing recently? What is the next major seasonal event to occur? Is it an equinox or a solstice? About what date will it occur? Will the current changes to day length and altitude of the Sun continue or will they stop and reverse? Explain.

To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

You have learned that it is the tilt of the Earth which is responsible for the seasons. However, the Earth-Sun geometry is not constant. In fact, the Earth's tilt varies from about 22.5 degrees to 25 degrees. What would happen to the Earth's climate if the tilt of the Earth increased? Decreased?

To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

In the early 1900s, Milutin Milankovitch, a Yugoslavian scientist who studied Earth-Sun relationships, proposed a radical (for that time) astronomical theory regarding climate change. Now called the Milankovitch Theory, his ideas were based on three seasonal astronomical factors:
1) the Earth's elliptical orbit around the Sun varies during a 100,000-year cycle,
2) the Earth's axis wobbles over a 26,000-year cycle,
3) the Earth's axial tilt varies over a 2 degree range during a 40,000-year period.
Milankovitch concluded that the interaction of these Earth-Sun relationships produces a 96,000-year broad climatic cycle over the globe.

Milankovitch's work was not accepted by the scientific community during his lifetime. However, it has stimulated a great deal of recent research trying to explain climatic cycles and global climate change. The NOAA Paleontology Program and the NASA Earth Observatory Library both contain further information on the Milankovitch Theory.

Based on information from these sites (and others if you choose to expand your knowledge further), write a brief essay summarizing the Milankovitch Theory of climate change. What is your opinion of its validity? Has evidence been found which supports the theory?

To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

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